Question

I’m starting developing app in WindowsPhone, and had some problems. I trying to add a canvas dynamically, but it does not work, I may forgot about something, could you help to spot my error? Code below is from my learning app, it is basic Win Phone app.

cs code:

public MainPage()
    {
        InitializeComponent();

        int size = 50;
        Canvas myCanvas = new Canvas();
        Canvas.SetLeft(myCanvas, 0);
        myCanvas.Width = size;

        Color c = new Color();
        c.R = 255;
        c.B = 0;
        c.G = 255;

        myCanvas.Background = new SolidColorBrush(c);

        ContentPanel.Height = 100;
        ContentPanel.Width = 100;
        ContentPanel.Children.Add(myCanvas);
        ApplicationTitle.Text = ContentPanel.ActualHeight.ToString();

    }

xaml

    <Grid x:Name="LayoutRoot" Background="Transparent">
    <Grid.RowDefinitions>
        <RowDefinition Height="Auto"/>
        <RowDefinition Height="*"/>
    </Grid.RowDefinitions>

    <!--TitlePanel contains the name of the application and page title-->
    <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
        <TextBlock x:Name="ApplicationTitle" Text="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>
        <TextBlock x:Name="PageTitle" Text="page name" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
    </StackPanel>

    <!--ContentPanel - place additional content here-->
    <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">

    </Grid>
</Grid>

Answer 1

I’m not quite sure what you’re trying to accomplish here with the Canvas. You may want to look into other controls to get what you’re trying to do.

That being said, the problem is that you are missing your “Alpha” component in the color. This is making it transparent.

Change:

    Color c = new Color();
    c.R = 255;
    c.B = 0;
    c.G = 255;

    c.A = 255;  // this is what you need to add to make it visible.